Photovoltaic modules generate Direct Current (DC) voltages. Typically, the DC voltage and DC current from one photovoltaic module is well below the needs of the voltage and current needed for the Alternating Current (AC) power grid. Typically, many photovoltaic modules are used in combination within a photovoltaic power generation system to provide the necessary voltage and current for the AC power grid. The DC voltages/currents also need to be converted to AC voltages/currents.
One significant challenge is to operate the photovoltaic modules for maximum power efficiency. For at least some photovoltaic modules, there is an output voltage at which the photovoltaic module will produce a maximum power output. The maximum power can vary with factors such as solar radiation and temperature of the photovoltaic panel. Moreover, the conditions at the various photovoltaic modules can differ from each other. Thus, for the photovoltaic power generation system to operate at or near optimum power efficiency, the various photovoltaic modules might need to be operated at different output voltages.
There are also challenges with operating other power generation systems, such as those that provide power from a collection of DC batteries.